The present invention relates to the supply of power over signaling wires used for data communication and more specifically, to the detection of a broken wire in a data communication system, such as a Power over Ethernet (PoE) system.
PoE is becoming increasingly common for a number of reasons. When signal wires are provided that permit communication from a data sourcing device to a remote device, by providing power to the remote device over the signal wires, one need not couple the remote device to another source of power. This can avoid the need to include a power supply in a Powered Device (PD) that is powered from an AC power source and additionally, minimizes cabling which can be costly. Moreover, the addition of a power supply to remote devices that are communicably coupled to a communication system via an Ethernet cable can add significant cost, weight and size to such a remote device. By using a PoE system, the disadvantages of self-powered remote devices are avoided.
When powering remote devices in a PoE system, there is a need to be able to detect broken wires in power feeds. Absent the ability to detect a broken wire in such a system, cables may overheat. The overheating of cables can pose a risk of fire and can result in permanent degradation of the cable.
For the above reasons it would be desirable to have a reliable and inexpensive system and method for detecting a broken wire in a PoE system.